It calculates the ability of eight regions to balance large shares of variable renewable energy:

The British Isles (Great Britain and Ireland together): 31%

Denmark: 63%

the Nordic Power Market (Denmark, Finland, Norway and Sweden): 48%

the Western Interconnection of the United States: 45%

the New Brunswick System Operator in Eastern Canada: 37%

Mexico, 29%

the Iberian Peninsula (Spain and Portugal together): 27%

Japan: 19%.

The book does this with a four-step Flexibility Assessment (FAST) method for assessing existing flexible resources, which can then be used to balance increasingly variable supply and demand:

assess the ability of the different flexible resources to change their production or consumption

examine the aspects of the power system that will constrain them from doing so

calculate the maximum requirement for flexibility of a given system resulting from fluctuating demand and output from wind plants and the like

identify how much more variability can be balanced with existing flexible resources.

“While some areas are clearly more flexible than others, all power areas assessed show that greater technical potential for balancing variable renewable energy output exists than is commonly supposed,” said Richard Jones, the IEA Deputy Executive Director, when launching the book at EREC 2011, Europe’s Renewable Energy Policy Conference, on 24 May in Brussels.

“The results from these case studies demonstrate that variability needs not be an impediment to deployment,” he continued. “As long as power systems and markets are properly configured so they can get the best use of their flexible resources, large shares of variable renewables are entirely feasible from the balancing perspective.”

News Editor of Energy and Environmental Management Magazine, the author of Solar Technology, The Earthscan Expert Guide to Using Solar Energy for Heating, Cooling and Electricity, and Sustainable Home Refurbishment: The Earthscan Expert Guide to Retrofitting Homes for Efficiency, and blogger at The Low Carbon Kid. Director of Green Deal Advice

Intermittency is a huge problem if your goal is to stop burning fossil fuel to make electricity. A 30% reduction would be a good first step, but only if that step didn't require a series of breakthroughs to get the next 60%.

The reason we should aim for near 0% fossil in electrical production is that clean electricity is much easier than carbon-free transportation (particularly air and sea) and concrete. Expect these areas to be the last to see deep emission cuts.

Any environmentalist who wants to maintain 50-70% of our grid on fossil fuel, for the purpose of waiting for breakthroughs in variable renewables needs to rethink their assumptions.

This is a reminder that under the terms of use, TEC comments must be on point. So, let's keep discussion here on the IEA report, it's data, and conclusions. If you have criticisms of it that you can reference, please do.

Willem, I think you might be surprised by what is actually happening to tackle this problem. Rationing is not on the table and such talk is merely scaremongering. Do not hide your head in the sand; instead, read on...

In Germany, an interesting [http://www.youtube.com/watch?v=aNZgjEDPe24] pilot project at Kassel University has shown how tackling intermittency will work in practice. Germany absolutely will lead the way on this as it is a crucial means to meet its twin targets of eliminating nuclear power while reducing carbon emissions.

The smart grid will be vital in balancing demand and supply, and an EPRI report [http://my.epri.com/portal/server.pt/gateway/PTARGS_0_234325_317_205_776_43/http%3B/uspalecp604%3B7087/publishedcontent/publish/epri_analysis_estimates_costs_benefits_of_fully_developing_smart_grid_da_777189.html] suggests that by enabling greater integration of renewable technologies, as well as reducing consumption, the smart grid could cut US 2030 carbon emissions by a staggering 58%, against a 2005 baseline. The benefits to society will far outweigh the costs - by up to $2,028 billion, EPRI says. In Britain, the savings to consumers are calculated at £7.3 billion.

Another crucial issue here is energy storage. Renewable energy generated for electricity (and of course all electricity) can be stored in a number of ways for use when needed:

* landfill, sewage gas or biogas generated by anaerobic digestion and algae can be stored conventionally ready for use in a gas-fired power station that can be fired up at a moments notice * hydrogen can be generated to be stored ready for use in a similar way * pumped storage for hydroelectric generation, as in the North Wales Dinorwig plant, built in 1984 * molten salts can store heat for up to 18 hours, which can then be used to drive turbines. This is being used in concentrated solar power stations in the US. Another system is described here: http://www.zeitnews.org/energy/another-cheap-way-to-store-solar-and-wind... * flywheels - being developed by, amongst others, America's Beacon Power, as an energy storage system on a grid-scale. Gene Hunt from Beacon Power gave a presentation recently which showed that that the system’s response time of four seconds is superior to fossil fuel plants taking up to five minutes, given that signals from energy operators can change every few seconds. He said market and regulatory reform present a central challenge, suggesting the creation of an energy storage regulatory category separate from energy generation. [http://2ndgreenrevolution.com/2011/03/08/world-future-energy-summit-wfes-2011-%e2%80%9ctechnology-forum%e2%80%9d-touches-on-all-major-green-technologies/#ixzz1O0dJqscE]

Another crucial point to understand is that because electricity has so far been tough to store and has had to be consumed as soon as it has generated, then this has dominated energy planning - forcing the construction of sufficient generation plant to meet peak demands.

But as soon as demand is managed better by the smart grid, and electricity can be stored, then this reduces the need for so much generation capacity.

So we save money and emissions by not needing so many polluting plants. Consumers benefit. Taxpayers benefit. The planet benefits. And no need for rationing. It's a triple-win pathway.

David,
Is there any Practical difference between "reducing consumption"/managing demand, and Rationing?
BTW I am all for technologies which enable on-demand availability of power, and Molten salts are a step in that direction, but the energy stored in molten salts is fixed at sunset, and it cannot be ramped up on demand , in other words, we'll all have to share whats available by sunset, unless we fire up the Natural Gas turbines. This is why I am taking the stance that this looks suspiciously like back-door rationing.

A guest says:

Amelia,

I have inserted images, including cartoons, previously. I do it, on occasion, because the images are effective.

The article from the London Daily Telegraph, for example, was more impactful than my describing it would have been. The content is so inconsistent with our experience that it is almost unbelievable. I suspect that the CEO of National Grid wishes he had been more circumspect; or, that the power had been out when he made the comment.

A guest says:

Intermittent wind and solar is a huge problem requiring inefficient gas peakers, or turning down low cost clean hydro as with BPA in the Northwest. Then there is the scale issue. Public Service of New Mexico has a 30,000 panel solar array. It would take 10,000 of them to begin to equal the Prairie Island(MN) nuclear plant.

Industrial solar and wind need very large taxpayer direct cash subsidies and 'must take' inflated power rates.There is a place for them as supplements, not substitutes.

I refer you to the book, which has its own analysis of the figures, which do not match yours. This is the International Energy Agency we're talking about, an organisation normally highly conservative on renewables and projections of future energy needs.

David, I am certainly not going to run out and buy a book, but as far as I can tell from your post the IEA is saying that Balancing Intermittent sources is "Feasible", and it assigns a "%" value to indicate such feasibility. What it does not do (or seem to do), is deal with the cost of balancing intermittent sources. As far as I see, Willem's post is saying that the costs worldwide is huge. I see no contradiction in that statement with the IEA. One last point. From my standpoint as a US resident, I don't care about feasibility if it means that we will have to Ration out power. If the rout to balancing power is to cut off demand sources in order to mach the intermittent and variable output, this solution may be "Feasible" to the IEA, but not to me.*

Whereas the POTENTIAL surely exists to balance wind power, the real world power systems are not arranged for it. The cost of rearranging the world's power systems would be many TRILLIONS of dollars and take many decades. A better alternative would be increased energy efficiency; far less costly per dollar invested.

A 10,000 MW wind facility needs a 10,000 MW balancing facility consisting of a mix of gas-fired OCGTs and CCGTs. If the wind facility has a CF = 0.31, the balancing facility has a CF = 1.0 - 0.31 = 0.69.

The estimated capital cost of the balancing facility would be about 10,000 MW x $1,250,000/MW = $12.5 billion, plus augmentation of gas supply lines and transmission systems. Any cycling facility must be utility-owned, not IPP-owned, to ensure it is available for cycling operations.

The balancing facility would operated well below its most efficient point which is near rated output; in fact, its average heat rate would be about 20% less than its rated heat rate.

If a mix of OCGT, CCGT and coal plants is used, as in Colorado and Texas, the extra CO2 emissions due to cycling would be significantly greater/kWh, because coal plants and their air quality control systems are highly unsuitable for frequent, rapid cycling, as shown in the Bentek study.

Because the annual-average CO2 emissions of the New England Electric Grid is about 1.0 lb of CO2/kWh (low compared to other grids due to CO2-free nuclear and hydro power), wind proponents claim a CO2 emissions reduction of 1.0 lb of CO2/kWh of wind power, whereas it is (1.0 - 0.587) = 0.413 lb of CO2/kWh, almost 60% less than claimed by wind proponents.

- "rearranging the world's power systems would be many TRILLIONS of dollars and take many decades" ; first of all, we try to discourage all caps that aren't acronyms on TEC. Also, the world's power systems are going to be rearranged- like it or not. It will take a lot of money, amount unknown, and hopefully not so many decades. Those two things- cost and time- are uncertain and hinge on political resistance.

- I'm with you on efficiency, but it can't do it all.

- "As you can see balancing wind power, already more expensive than fossil power, is not for free." - I don't think the author is suggesting that it is. We've already seen wind costs fall radically in the last 10 years; it doesn't seem logical to me to forsee them at the current level as the market grows. We can't stay on high carbon fossil resources based on environmental harm alone, so it seems like changes must happen, expensive or otherwise. There's also little reason to think that carbon resources will stay cheap. The cost of coal is rising with global demand too.

The extra fuel costs of accommodating wind power is about $0.0155/kWh, about 3 times the total fees currently charged for accommodating wind power.

The extra owning (shorter useful service life due to cycling) and extra O&M costs (due to cycling) of the cycling facility required to accommodate wind power are not included in the $0.0155/kWh.

Wind power facility owners are getting a huge free ride by using the cycling capability of the existing grids but not fully paying for all the cycling costs. Utilities have not fully identified, quantified and included all the cycling costs in their current fees. I estimate the fee should be greater than $0.03 per kWh, instead of the current $0.05/kWh.

I don't disagree that wind -or any- facilities should internalize their externalities, and you may be right that costs are lower than they should be. But, can't we say that about all forms of energy? I can't think of one type of energy that isn't somehow subsidized, or protected from the market to some degree. I want all energy industries to fully internalize their costs, and most don't.